Flow heater



R. E. WELCH Oct. 24 1944o FLOW HEATER Filed Feb. 2, 1942 3 Sheets-Sheet2 ocr. 24, 1944e R," E. WELCH 2,361,252

FLOW HEATER Filed Feb. 2. 1942 5 Sheets-Sheet 3 RQbewEx/zch,

Patented Oct. 24, 1944 UNITED STATES PATENT oFricE FLOW HEATER Robert`E. Welch, Houston,l Tex., assignor to Nowery J. Smith, doing businessas, Nowery J. Smith Supply Company, Houston, Tex.

Appiication February 2, 1942, serial No. A429,351

(c1. cs2- 1) 2 Claims.

The present invention relates to a flow heater for oil Wells.

It is a principal object of the invention to provide suitable apparatusfor heating the high pressure wet gas as it flows -directly from theoilweil.

A further object of the invention is to provide apparatus foryautomatically heating the high pressure wet gas ilow from an oil well,so that a denite temperature of the oilwell flow may be maintained afterthe high pressure flow has been reduced to a pressure suitable forseparating.

Many oil wells in use today produce a very high pressure wet gas, thepressure of which must be greatly reduced before it can be separatedinto its components of oil, water, and gas. Itis common practice to heatthe high pressure flow from the well, so that the ow will not freezewhen the pressure is reduced, in view of the scientific fact thatreducing the pressure of a gas also causes a cooling of the temperatureof the gas. If the high pressure flow from the well were reduced inpressure at well temperature, great diiliculty would be experienced,because the iiow wouldfreeze and the pressure regulating valves wouldfreeze. By my invention, I have provided an oil well flow heater ,whichis automatically regulated so that a deiinite and controlled temperaturej of flow at reduced pressure is obtained, and the 'possibility that theiiow will freeze and the/pressure regulators freeze is avoided.

- It is a further object of my invention to provide an oil well owheater construction, in which the supply of fuel to the heater burnersis thermo- Y statically controlled in response to thetemperature of theheated oil well flow after pressure reduction. p

Further objects and advantages of the invention will be readilyunderstood from the accompanying description and drawings, in which:

Figure 1 is an elevation of the complete heater apparatus, including thepressure reducing regulators and the thermostatic` burner controls; y

Figure 2 is a vertical section of the heater tank, showing the) burner,ilues, and iiow conducting pipe or coil partly in elevation;

Figure 3 is a cross sectional view taken on\the line 3 3 of Figure 2,showing the details of the u able manner.

of the float controlled water supply to the upper water compartment ofthe heater.

Referring to the drawings, in which like n merals indicate like parts, iindicates generally the'vertical upright tank comprising the main heaterstructure. The vertical tank i is divided into an upper water-containingcompartment 2 and a lower rebox compartment 3 by a iianged and dishedsteel head d, constituting the domeshape'd head of the rebox. Extendingfrom the steel head 4 through the upper water-containing compartment2are a series of flues orre tubes 5. These tubes extend above the levelof the water in the compartment 2 and communicate with the atmospherethrough the hood and chimney structure 6. Positioned within the upperwater-containing compartment 2 Vand coiled in proximity to the iiues 5,is a flow conducting` pipe 1. This pipe enters the tank at 8, and isprovided `on the inlet side with a cut-'off valve 8a., by means 4ofwhich the flow conducting/,pipe 'i may' be valved andconnected to thesource of high pressure flow from the well. The flow conducting pipe 1is provided with the outlet pipe 9 for conducting the heated ow to thepressure reducing and regulating valve `2i` to be described hereinafter.

Positioned within the rebox 3 are a plurality of low pressure vgasburners Ill. These burners are nested in a group in the center of therebox and y are'llsupplied with a source of warm dry gas as fuel, bymeans of the fuel supply pipe I l A pilot burner I2 is also provided,which ls intended to be burning at all times and is supplied with fuelthrough the pipe I3. Air supply tubes I4 for the burners are positionedin the bottom of the firebox and are provided with damper valves i5 tocontrol the amount of 'air supplied to the burners. These damper valvesare shown as manually oper` ated, although they may be operated in anysuit- A irebox door i6, by means of which access to the rebox may behad, is shown in Figure 1 of the drawings.

The upper water-containing compartment of the heater is supplied withwater through the positioning of the burner iiues within the tank; thelevel of the water line is an overow pipe vFigure 4 is a cross sectionalview taken on the line 4 4 of Figure 2, and showing the details of theburners and the air supply tubes in the fhebox,

and

Figure 5 is a fragmentary view, showing a detail opening I8, which willcarry away any excess amount of Water in the tank, should the floatoperated valve l1 fail to function. The upper compartment 2 is alsoprovided with a waterlevei sight gage i9, and a thermometer 20, by meansof which conditions of the water in the upper compartment may beascertained.

The heated high pressure oil well flow, after passing through the owconducting pipe or coil 1, is conducted through the outlet pipe 9 to thepressure regulator valve, indicated generally at 2| where its pressureis reduced to the desirable pressure for further treatments, such asseparating or the like; In order to make repairs on the pressureregulator, should they be necessary, a by-pass system is provided toshunt the iiow around the pressure regulator. Valves 22, 23, and 24,together with a piping 25, constitute the by-pass arrangement, and itcan be readily seen that by closing the valves 22 and 24. and openingthe valve 23, the iiow will be by-passedv around the pressureregulator.4 After leaving the pressure regulator, the flow is conductedthrough the pipe 26 to the thermowel 21, which contains the actuatingbulb 28 of the thermostat valve 29 controlling the fuel supply to theburner I0. A temperature indicator 49 is positioned onv the thermowel 21to indicate the temperature of the reducedl pressure oil well ow. 'I'hetreated iiow then passes through the pipe 30 to the separator apparatusor other apparatus, which is desired to be used to treat the oil wellflow.

' The low pressure burners l0 lused in this apparatus are supplied withgas as a fuel, of which there is a great abundance in most oil fields,and this gas is usually cold and of high pressure. Y It is, therefore,necessary to warm the fuel gas and reduce its pressure, andi I haveprovided in my invention apparatus for performing this function. Thecool dry fuel gas is supplied through the pipe 3| and passes through ahairpin coil 32 withinA the upper water-containing compartment rof theheater, whereby the fuel gas is warmed. The fuel gas then passes througha pressure regulator 33 and the,pipe`34 to the pressure reducingapparatus. In view of the high pressure of the gas, I have provided twopressure reducing regulators 35 and 36 to reduce the fuel gas to thevery .lowV pressure needed for the low pressure burners 4lll. The yhighpressure lfuel gas first passesthrough the pressure regulator 35. A T

fitting A31 is provided to branch the reduced pressure fuel gas into twolines. Some of the reduced pressure gas is conducted through the pipe 38and the shut-off valve 39 to the pipe I3 which supplies the pilotburner-with fuel. A pressure indicator 4D is shown to indicate thepressure ,of the fuel supply to the pilot. 'I'he warmed dry gas 31through thek pipe 4| to the .pressure regulator 38. This further reducesthe pressure of the fuel gas so that it islow enough to properly burn inthe' low pressure burners. pressure fuel gas is conducted through thepipe 42 from the pressure regulator 3B to the thermostaticallycontrolled valve .29 which is responsive to the temperature of the oilwell flow as it passes the thermowel y21. Theithermostatically regulatedlow pressure fuel gas as supplied by the thermostatic valvey29, thenpasses throughthe This warm and low the pressure regulator 38 andthermostatic valve 29. A press'ure indicator 41 may be used to indicatethe pressure vof the fuel gas supply to the low pressure burners.

The pressure regulator 2| for reducing the pressure of the heated highpressure oil well ow is of 'the standard construction operated bydiaphragms, and in order to prevent freezing, is supplied with asourceof warm highpressure gas conducted through the tubing l48 connected tothe down-stream side of the hairpin coil 32. The warm dry gas conductedthrough the tube 48 is used to operate the diaphragms in the pressureregulator 2|, and thus minimize the possibility that the pressureregulator will freeze.

As the pressure4 regulator valves, shut-off valves, thermowel, andthermostatically-controlled valve are all of standard manufacture, itwill be readily understood that my invention is not limited to the useof any specific forms of these mechanisms, but that any suitablesubstitutes may be used.

In operating my flow heater, the flow from the oil wells which is mainlya high pressure wet gas, is conducted through the iiow conducting pipe 1coiled within the upper water-containing compartment 2. This coil is inproximity to the rebox tubes or fiues 5, and the heat of burning gasespassing through the flues 5 will be transmitted through the water in theupper compartment 2 to the coil 1. This results in a heating of the highpressure wet gas flowing through the coiled pipe 1. The heated highpressure flow then passes through the outlet pipe 9 to the pressurereducing regulator 2|. After the pressure of the heated oil well ow isreduced the temperature of the reduced pressure flow is obtained. Thethermowel 21 and the actuating bulb 28 of thethermostatically-controlled valve 29 are operated in response to thistemperature of the reduced pressure flow. The thermostatic valve 29controls the operation of the burners I0 which supply the heat to theupper water 'i at reduced pressure also passes from the T fittingcompartment 2, and hence to the high pressure wet gas flow from thewell.

'I'hus it'will be seen that I have provided apparatus for heating thehigh pressure flow from an oil well and controlling the amount of heatsupplied to said high pressure flow in accordance with the temperatureof the reduced pressure flow, so that a definite temperature of reducedpressure flow may be maintained. By operating my thermostatic valve onthe fuel supply to the burner in response to the temperature ,of thereduced pressure oil well flow, I canvobtaina denite control of thetemperature of the reduced oil well flow as it passes the outlet pipe30.

`In the appended claims, the term fiow" is intended to mean the Wet gasflowing directly from oil and gas wells.

I claim:

1. In an apparatus of the character described, an upright tank having anupper water compartment and a lower firebox compartment, a burner insaid rebox. a series of vertical flues extending from the fireboxcompartment through the water compartment to communicate'with theatmosphere, a line including a flow conducting pipe coiled in proximityto the flues within said upper compartment, said line being adapted 'tobe connected to a' source of high pressure gas flow from an oil well,pressure reducing means in said line beyond said tank, and means Vtocontrol the supply of fuel to the burner in said,-

to the temperature in said line beyond said pressure reducing means.

2. In an apparatus ofthe character described,

, a line adapted to be connected to an oil wel] to receive warm highpressure gas from the latter, a pressure reducer in said line, a secondline adapted to be connected to a source of cold high pressure gas,gas-tired means to heat said second line and to also heat saidfirst-named line at a point in advance of said pressure reducer, saidsecond line leading to said heating means to supply gas fuel to thelatter, and temperature responsive means in said first-named linebeyond' said pressure reducer to control the flow in said second line.

ROBERT E. WELCH.

